According to a new study, 19 huge earthquakes have occurred over the past 10,000 years along the Pacific Northwest’s Cascadia Subduction Zone, each typically 8.7 to 9.2 on the Richter scale.  This most comprehensive study of earthquake history off the Pacific Northwest coast suggests that there is a 40% chance of such an event happening in the next 50 years — but the probability is different in different locations. Read more here; ESS affiliate Art Frankel is quoted.